Producing branched trialkyl aluminum and branched alcohols therefrom

Abstract

The present disclosure provides a method for producing a branched trialkyl aluminum and branched alcohols therefrom. The method of producing the branched trialkyl aluminum comprises providing a reaction mixture of (a), (b) and (c), where (a) is an alpha-olefin; (b) is a trialkyl aluminum; and (c) is a catalyst system comprising a procatalyst;; and an activating cocatalyst; and reacting (a) and (b) in the presence of (c) to produce the branched trialkyl aluminum of Formula (IV)

Description

[0001]Producing Branched Trialkyl Aluminum and Branched Alcohols Therefrom Technical Field The present disclosure provides a method for producing a branched trialkyl aluminum and branched alcohols therefrom. Background Branched alcohols are alcohols in which the parent carbon chain having the hydroxyl group (-OH) also includes one or more carbon chain substituents or “branches” extending from the parent carbon chain. Compared to straight-chain (linear) alcohols, branched alcohols have a more complex structure, which can affect the properties of the alcohol. For example, branched alcohols often have lower boiling points as compared to their straight-chain counterparts. In addition, branched alcohols often have lower freezing points compared to linear analogues, which is desirable in some application. Isopropanol (rubbing alcohol) and iso-butanol are common examples of branched alcohols. Branched alcohols have a variety of important applications. For example, branched primary alcohols are used as starters for industrial surfactants (e.g., ionic and non-ionic surfactants) and as solvents in the areas of coatings, cleaning formulations and inks. Branched primary alcohols are also used in the areas of lubricants and polymer additives, among other uses. There can, however, be challenges in producing branched primary alcohols. For example, there can be challenges in selectivity and efficiency in their production. During production processes, there can be competition between forming the desired branched alcohol and other less desired products, including straight-chain alcohols, which lead to difficulties in both isolation and production efficiencies. Finding ways to favor the production of branched alcohols is therefore an important and ongoing need in the art. Summary Embodiments of the present disclosure address the above identified shortcoming in the production of branched alcohols. Specifically, the present disclosure utilizes one or more species of alpha-olefin with one or more species of a trialkyl aluminum in the presence of a catalyst system having a procatalyst and an activating cocatalyst to generate branched trialkyl aluminum species. The branched trialkyl aluminum species can then undergo oxidation and hydrolysis to produce the desired branched alcohol(s), as discussed herein. Embodiments of the present disclosure can produce branched alcohols with differing molecular weights that depend on the trialkyl aluminum employed. The parent carbon chain of the alpha-olefin can form the backbone of the branched alcohol, while the alkyl of the trialkyl aluminum employed provides the branch of the resulting branched alcohol. Alternatively, the alkyl (or alkyls) of the trialkyl aluminum employed can form the backbone of the branched alcohol, while the parent carbon chain of the alpha-olefin can provide the branch of the resulting branched alcohol. Such reactions are seen in the Reaction Schemes provided herein. Embodiments of the present disclosure can be undertaken with one or more (e.g., a mixture) of alpha-olefins, and one or more (e.g., a mixture) of trialkyl aluminums, including heteroleptic trialkyl aluminum, to provide a broad distribution of branched alcohols. Using the methods of the present disclosure, alcohols and preferably branched alcohols, including branched primary alcohols can be produced. For the various embodiments, the present disclosure provides a method of producing a branched trialkyl aluminum that comprises providing a reaction mixture of (a), (b) and (c), where (a) is an alpha-olefin of Formula (I): where R1is a C2 to C18 alkyl; (b) aluminum of Formula (II): where each of R2, R3and from a C1 to C24 alkyl; and where (c) is a catalyst system comprising a procatalyst of Formula (III): where for X1each to C4 alkyl; R5-R13are independently in each occurrence hydrogen, halogen, substituted or unsubstituted C1 to C20 alkyl, or substituted or unsubstituted C6 to C20 aryl, or two or more adjacent R groups are joined together thereby forming a saturated, unsaturated, or aromatic ring; and an activating cocatalyst; and reacting (a) and (b) in the presence of (c) to produce the branched trialkyl aluminum of Formula (IV): . For the various alkyl. In additional embodiments, R1 can be a C4 to C10 alkyl. For the various embodiments, R1can have an even number of carbons. For the various embodiments, each of (a) the alpha-olefin of Formula (I) in the reaction mixture can have the same R1moiety. In addition embodiments, two or more of (a) the alpha- olefin of Formula (I) in the reaction mixture can have a different R1moiety. For the various embodiments, each of R2, R3and R4can be independently selected from a C3 to C24 linear alkyl. In additional embodiments, each of R2, R3and R4can be independently selected from a C2 to C10 alkyl. In further embodiments, each of R2, R3and R4can be independently selected from a C2 to C6 alkyl. For the various embodiments, each of the alkyl of R2, R3and R4can have an even number of carbons. For the various embodiments, for Formula (II) two or more of R2, R3and R4can have the same size alkyl moiety. In addition embodiments, the trialkyl aluminum of Formula (II) can be heteroleptic. In a specific embodiment, R1can be a C10 alkyl and each of R2, R3and R4can be a C2 alkyl. For the various embodiments, the branched alcohol can be a 2-ethyl branched alcohol having C6 to C20 total carbons. For the various embodiments, the procatalyst of Formula (III) can be present in the reaction mixture at a molar equivalent of 0.01 to 0.0001 relative to (a) the alpha-olefin of Formula (I). For the various embodiments, the activating cocatalyst can be selected from the group consisting of [(C16-18H33-37)2CH3NH] tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, or ferrocenium tetrakis(pentafluorophenyl)borate. For the various embodiments, the procatalyst of Formula (III) is . For the various embodiments, the losure can further comprise oxidizing the branched trialkyl aluminum of Formula (IV) to produce an aluminum alkoxide; and hydrolyzing the aluminum alkoxide to produce a branched alcohol. Brief Description of Drawings FIG.11H NMR spectra of TEA / 1-hexene reaction mixture of EX 1. (A) before reaction, (B) after reaction. FIG.21H NMR spectra of TEA / 1-octene reaction mixture of EX 2. (A) before reaction, (B) after reaction. FIG.31H NMR spectra of TEA / 1-decene reaction mixture of EX 3. (A) before reaction, (B) after reaction. FIG.41H NMR spectra of TEA / 1-dodecene reaction mixture of EX 4. (A) before reaction, (B) after reaction. FIG.51H NMR spectra of TEA / 1-dodecene reaction mixture of EX 5. ½ catalyst dosage. (A) before reaction, (B) after reaction. FIG.61H NMR spectra of reaction mixture. (A) before reaction, (B) after reaction of EX 6. FIG.7 Temperature histories of overhead vapor, pot liquid and heating mantle during distillation separation of EX 6. Detailed Description Embodiments of the present disclosure address the above identified shortcoming in the production of branched alcohols. Specifically, the present disclosure utilizes one or more species of alpha-olefin with one or more species of a trialkyl aluminum in the presence of a catalyst system having a procatalyst and an activating cocatalyst to generate branched trialkyl aluminum species. The branched trialkyl aluminum species can then undergo oxidation and hydrolysis to produce the desired branched alcohol(s), as discussed herein. Embodiments of the present disclosure can produce branched alcohols with differing molecular weights that depend on the trialkyl aluminum employed. The parent carbon chain of the alpha-olefin can form the backbone of the branched alcohol, while the alkyl of the trialkyl aluminum employed can provide the branch of the resulting branched alcohol. Alternatively, the alkyl (or alkyls) of the trialkyl aluminum employed can form the backbone of the branched alcohol, while the parent carbon chain of the alpha-olefin can provide the branch of the resulting branched alcohol. Such reactions are seen in the Reaction Schemes provided herein. Embodiments of the present disclosure can be undertaken with one or more (e.g., a mixture) of alpha-olefins, and one or more (e.g., a mixture) of trialkyl aluminums, including heteroleptic trialkyl aluminum, to provide a broad distribution of branched alcohols. Using the methods of the present disclosure, alcohols and preferably branched alcohols, including branched primary alcohols and those with at least one branch, are produced. The method of the present disclosure addresses the technical problem of producing branched alcohols, in particular branched primary alcohols, using low catalyst loading in producing the trialkyl aluminum of the present disclosure. Specifically, the present disclosure utilizes a catalyst loading for the procatalyst, as provided herein, of the catalyst system at a molar equivalent, relative to (a) the alpha-olefin, , of 0.01 to 0.0001, where values below 0.0001 are possible. Such catalyst loading is far lower than currently known and helps to improve the efficiency and economics of producing the trialkyl aluminum of the present disclosure. For industrial applications, the branched alcohols of the present disclosure produced from the trialkyl aluminum are desirable starters for ionic and non-ionic surfactants. In particular, branched alcohols of the present disclosure having branch lengths from C1 to C4 are among the most desirable branched alcohols as they can yield alcohol derivatives that are more readily biodegradable. As used herein, a branched alcohol is an alcohol molecule in which the parent carbon chain that contains the hydroxyl group includes at least one branch point intermediate between the ends of the parent carbon chain and from which an alkyl group extends as a substituent. As used herein, a branched primary alcohol includes a structure in which the carbon atom bonded to the hydroxyl group (-OH) is bonded to only one other carbon atom of a carbon atom chain, and where at least one carbon chain branch extends from the carbon atom chain containing the hydroxyl group. As used herein, alpha-olefin and 1-alkene can be used interchangeably. For the various embodiments, the present disclosure provides a method of producing the branched trialkyl aluminum that comprises providing a reaction mixture of (a), (b) and (c), where (a) is an alpha-olefin of Formula (I): I) where R1is a C2 to C18 alkyl; (b) is aluminum of Formula (II): where each of R2, R3and R4is a C1 to C24 alkyl; and where (c) is a catalyst system comprising a procatalyst of Formula (III): where for X1or a C1 to C4 alkyl; R5-R13are independently in each occurrence hydrogen, halogen, substituted or unsubstituted C1 to C20 alkyl, or substituted or unsubstituted C6 to C20 aryl, or two or more adjacent R groups are joined together thereby forming a saturated, unsaturated, or aromatic ring; and an activating cocatalyst; and reacting (a) and (b) in the presence of (c) to produce the branched trialkyl aluminum of Formula (IV): . For the various intermediate and / or incomplete Al species containing mixtures of Al reagents somewhere between Formulas IV and II. (a) Alpha-Olefin For the various embodiments, R1of the alpha-olefin of Formula (I): can provide, or result in, a linear alpha- alpha-olefin, where mixtures of both the linear alpha-olefin and the branched are possible for use in the reaction mixture discussed herein. As noted above, R1is selected from a C2 to C18 alkyl. Preferably, R1can be a C2 to C14 alkyl. More preferably, R1can be a C4 to C12 alkyl. In an additional preferred embodiment, R1can be a C4 to C10 alkyl. In addition, for the various embodiments R1can have an even number of carbons. So, specific examples of the alpha-olefin of Formula (I) can therefore include, but are not limited to, 1-hexene (when R1is C4), 1-octene (when R1is C6), 1- decene (when R1is C8), and 1-dodecene (when R1is C10). For the various embodiments, the reaction mixture of (a), (b) and (c) can include the same alpha-olefin for (a) or a mixture of two or more different alpha-olefins for (a). For example, for the various embodiments each of (a) the alpha-olefin of Formula (I) in the reaction mixture can have the same R1moiety. So, for example, in this embodiment, all of (a) used in the reaction mixture could be 1-hexene, or 1-octene, or 1-decene, or 1-dodecene. In alternative embodiments, two or more of (a) the alpha-olefin of Formula (I) in the reaction mixture can have a different R1moiety. So, for example, when two of (a) are present in the reaction mixture a first part of (a) can be a first alpha-olefin of Formula (I) having a first R1moiety, and a second part of (a) can be a second alpha-olefin of Formula (I) having a second R1moiety, where the first part and second part of (a) together provide all of (a) in the reaction mixture, and the first R1moiety and the second R1moiety have a different number and / or configuration (e.g., linear and branched) of carbon atoms. Such an example can easily be understood to extend to a reaction mixture in which three or more of the (a) alpha-olefin are present in the reaction mixture, where each of three or more of the (a) alpha-olefin have an R1moiety with a different number and / or configuration of carbon atoms. For the various embodiments, the alpha-olefin of Formula (I) can be made by a variety of known processes. Such processes include, but are not limited to, the Shell Higher Olefin Process in which a mixture of even-numbered or odd-numbered linear alpha-olefins are produced via ethylene oligomerization / metathesis or using the Ziegler process via ethylene oligomerization and elimination to form even-numbered olefins. (b) Trialkyl Aluminum The reaction mixture further includes (b) the trialkyl aluminum of Formula (II): (II) where each of R2, R3and R4is independently selected from a C1 to C24 alkyl. For the various embodiments, the C1 to C24 alkyl can be a C1 to C24 linear alkyl and / or can be a C3 to C24 branched alkyl. Preferably, each of R2, R3and R4is independently selected from a C3 to C24 linear alkyl. Preferably, each of R2, R3and R4can independently be selected from a C1 to C10 linear alkyl. More preferably, each of R2, R3and R4is independently selected from a C2 to C10 alkyl. So, preferably each of R2, R3and R4is independently selected from a C2 to C10 linear alkyl. Even more preferably, each of R2, R3and R4is independently selected from a C2 to C6 alkyl. For such an embodiment, preferably each of R2, R3and R4is independently selected from a C2 to C6 linear alkyl. For the given embodiments, it is preferable that each of the alkyl moiety of R2, R3and R4can have an even number of carbons. Examples of such trialkyl aluminum of Formula (II) where each of the alkyl moiety of R2, R3and R4has an even number of carbons can be formed through the oligomerization of ethylene, as provided herein. For the various embodiments, for Formula (II) two or more of R2, R3and R4can have the same size alkyl moiety. For example, each of R2, R3and R4in Formula (II) can be a C2 alkyl (e.g., R2, R3and R4are each a C2 alkyl) or can be a C4 alkyl, or can be a C6 alkyl. In a specific embodiment, the reaction mixture can include (a) where R1of the alpha-olefin is a C10 alkyl and each of R2, R3and R4of Formula (II) is a C2 alkyl. In alternative embodiments, the trialkyl aluminum of Formula (II) can be heteroleptic. As used herein, heteroleptic refers to a coordination compound where the central metal atom, in this case the Al atom, is bonded to more than one type of ligand, in this case where any two or all three of the R2, R3and R4in Formula (II) are different size alkyl moieties. (c) Catalyst System Comprising Procatalyst and Activating Cocatalyst Procatalyst The (c) catalyst system of the present disclosure comprises a procatalyst and an activating cocatalyst as provided herein. For the various embodiments, the procatalyst of catalyst system (c) can be Formula (III): where for X1each to C4 alkyl, and preferably for each occurrence X1is methyl ; R5-R13are independently in each occurrence hydrogen, halogen, substituted or unsubstituted C1 to C20 alkyl, or substituted or unsubstituted C6 to C20 aryl, or two or more adjacent R groups are joined together thereby forming a saturated, unsaturated, or aromatic ring. For the above definitions, either or both of the C1 to C20 alkyl or the C6 to C20 aryl can independently be unsubstituted or substituted, where such substitutions can include, but are not limited to, methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-octyl, or tert-octyl. Exemplary procatalysts include: Formula (A): where for X1each to C4 alkyl, and preferably each occurrence X1is methyl (C1 alkyl); Rfindependently in each occurrence is hydrogen, halogen, a C1 to C20 alkyl, or a C6 to C20 aryl, or two adjacent Rfgroups are joined together thereby forming a ring, and f is 1-5; and Rcindependently in each occurrence is hydrogen, halogen, a C1 to C20 alkyl, or a C6 to C20 aryl, or two adjacent Rcgroups are joined together thereby forming a ring, and c is 1-5. An exemplary catalyst from Formula (A) includes: Activating Cocatalyst For the various embodiments, the procatalyst is activated with the activating cocatalyst as provided herein. For example, the procatalyst according to the procatalyst provided herein may be rendered catalytically active by contacting or combining the procatalyst with the activating cocatalyst. Additionally, the procatalyst as provided herein can include both a neutral procatalyst form, and a positively-charged catalytic form, which may be positively charged due to the loss of a monoanionic ligand. For the various embodiments, the activating cocatalyst can be selected from the group consisting of [(C16-18H33-37)2CH3NH] tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, ferrocenium tetrakis(pentafluorophenyl)borate and combinations thereof. In additional embodiments, suitable activating cocatalysts for use herein include the activating cocatalyst as provided herein and other neutral Lewis acids. Combinations of one or more of the foregoing activating cocatalysts and techniques are also contemplated. Lewis acid activating cocatalysts can include Group 13 metal compounds containing (C1−C20)hydrocarbyl substituents. In some embodiments, Group 13 metal compounds are tri((C1−C20)hydrocarbyl)- substituted-aluminum or tri((C1−C20)hydrocarbyl)-boron compounds. In other embodiments, Group 13 metal compounds are tri(hydrocarbyl)-substituted-aluminum, tri((C1−C20)hydrocarbyl)-boron compounds, tri((C1−C10)alkyl)aluminum, tri((C6−C18)aryl)boron compounds, and halogenated (including perhalogenated) derivatives thereof. In further embodiments, Group 13 metal compounds are tris(fluoro-substituted phenyl)boranes, tris(pentafluorophenyl)borane. In some embodiments, the activating cocatalyst is a tri((C1−C20)hydrocarbyl)ammonium tetra((C1−C20)hydrocarbyl)borate (e.g. bis(octadecyl)methylammonium tetrakis(pentafluorophenyl)borate). As used herein, the term “ammonium” means a nitrogen cation that is a ((C1−C20)hydrocarbyl)4N+a ((C1−C20)hydrocarbyl)3N(H)+, a ((C1−C20)hydrocarbyl)2N(H)2+, (C1−C20)hydrocarbylN(H)3+, or N(H)4+, wherein each (C1−C20)hydrocarbyl, when two or more are present, may be the same or different. The ratio of total number of moles of the procatalyst to total number of moles of one or more of the activating cocatalysts can be from 1:10,000 to 100:1. In some embodiments, the ratio is at least 1:5000, in some other embodiments, at least 1:1000; and 10:1 or less, and in some other embodiments, 1:1 or less. For the various embodiments, (a) and (b), as provided herein, are reacted in the presence of (c) to produce the branched trialkyl aluminum of Formula (IV): . For the various embodiments, reacting (a) and (b), as provided herein, in the presence of (c) can be done at a temperature in a range of 10 to 50oC and a pressure in a range of 100 kPa to 500 kPa. Preferably, (a) is in a liquid state where both the temperature and pressure of the reaction mixture are adjusted accordingly to ensure these reaction conditions. For the various embodiments, reacting (a) and (b) in the presence of (c) to produce the branched trialkyl aluminum of Formula (IV) is done such that for the reaction mixture (b) the trialkyl aluminum of Formula (II) is at a molar equivalent of 0.1 to 1 relative to (a) the alpha- olefin of Formula (I). Preferably, reacting (a) and (b) in the presence of (c) to produce the branched trialkyl aluminum of Formula (IV) is done such that for the reaction mixture (b) the trialkyl aluminum of Formula (II) is at a molar equivalent of 0.2 to 0.6 relative to (a) the alpha- olefin of Formula (I). In addition, molar equivalent of the procatalyst of the catalyst system (c) relative to (a) the alpha-olefin of Formula (I) for the reaction mixture is in a range of 0.0001 to 0.0004. Preferably, the molar equivalent of the procatalyst of the catalyst system (c) relative to (a) the alpha-olefin of Formula (I) for the reaction mixture is in a range of 0.00015 to 0.0003. The reaction mixture can be allowed to react under an inert atmosphere, such as under an atmosphere of nitrogen gas or other known inert gases. The inert atmosphere can also be dry, where such a dry inert atmosphere can contain less than 0.01 weight percent water based on the total weight of the gas of the inert atmosphere. For the various embodiments, the method of producing the branched trialkyl aluminum as discussed herein can be illustrated in the following Reaction Scheme (I): where . For the the present disclosure can further comprise oxidizing the branched trialkyl aluminum of Formula (IV) to produce an aluminum alkoxide, and then hydrolyzing the aluminum alkoxide to produce a branched alcohol. For the various embodiments, oxidizing the branched trialkyl aluminum of Formula (IV) can be accomplished by air oxidation using dry air (e.g., dry atmospheric air), dry oxygen gas or mixtures thereof (all of which are referred to herein as “dry oxidizing gas”). As used herein, dry oxidizing gas (e.g., dry atmospheric air, dry oxygen gas or mixtures thereof) can contain less than 0.01 weight percent water based on the total weight of the dry oxidizing gas. The oxidizing can be undertaken at increased pressure from 1 atm to 10 atm. Industrially the oxidation of trialkyl aluminums is typically done at pressure. For the various embodiments, the dry oxidizing gas can be bubbled and / or sparged through the branched trialkyl aluminum of Formula (IV). While the dry oxidizing gas is bubbled and / or sparged the branched trialkyl aluminum of Formula (IV) can be mixed or stirred. For the various embodiments, the branched trialkyl aluminum of Formula (IV) can also be suspended in a solvent, where suitable solvents include, but are not limited to, toluene. In addition, the temperature while oxidizing the branched trialkyl aluminum of Formula (IV) to produce an aluminum alkoxide can be maintained in a range of 10 to 50 °C. Such temperature control can be accomplished by regulating the flow rate of the dry oxidizing gas or removing heat from the process through known techniques (e.g., use of a temperature controlled reaction vessel). Reaction times for oxidizing the branched trialkyl aluminum of Formula (IV) to produce an aluminum alkoxide can range from 5 hours to 24 hours. The oxidation of aluminum alkyls can also be undertaken with the addition of a catalyst to promote oxidation or reduce oxidized impurities. Common catalysts are metal alkoxides such as Group 4 alkoxides [M(OR)4] that are exemplified by titanium tetraisopropoxide. Other viable metal alkoxides contain Group 12 and Group 13 elements, such as Zn and Al, respectively. The concentration of the catalyst can vary from 0.01 weight percent to 5% based on the total weight of the reaction composition. The hydrolysis process of aluminum alkoxides to the corresponding branched alcohols can be undertaken by reaction with a base, an acid, or water. Examples of alkaline aqueous solutions include Group 1 hydroxides, such as NaOH and KOH. Examples of acidic aqueous solutions include hydrochloric, sulfuric, and acetic acid. The concentration of basic or acidic solutions can vary from 0% by weight (neutral pH) to 30% by weight. The hydrolysis temperature can also vary with cooling applied to remove the heat generated from hydrolysis or heat can be added. It has also been shown in the literature that small MW alcohols such as MeOH and EtOH can be used to hydrolyze aluminum alkoxides to the corresponding alcohols. The resulting branched alcohol(s) produced in hydrolyzing the aluminum alkoxide can then be separated using known separation processes. Such separation processes include, but are not limited to, distillation and extraction techniques as are known in the art. Specific examples of preferred branched alcohols produced using the method of the present disclosure can include, but are not limited to, a 2-ethyl branched alcohol having C6 to C20 total carbons. Such preferred branched alcohols can be formed using triethyl aluminum for (c) of the reaction mixture and linear alpha-olefins for (a), where R1can be a C4 to C20 linear alkyl. For the present method triethyl aluminum is reacted with the linear alpha-olefin(s) to generate the 2- ethyl branched alcohols. The process shown in Reaction Scheme 2, below, which can generate the 2-ethyl branched alcohols having C6 (2-ethyl-1-butanol) to C20 (2-ethyl-1-icosanol) total carbons. As illustrated in Reaction Scheme 2, the linear alpha-olefin(s) are made through ethylene oligomerization and displacement, where this process generates a distribution of linear alpha-olefin(s) with concomitant production of triethyl aluminum, when ethylene is used as the displacement species. As illustrated, the coproduced triethyl aluminum can be recycled back to generate more linear alpha-olefin(s) or used for a (c) in the formation of branched aluminum alkyls. Reaction Scheme 2 Reaction Scheme 2 can also be broadened to include trialkyl aluminums synthesized by the Ziegler process. As known, the Ziegler process involves the production of fatty alcohols from ethylene using trialkyl aluminum in a two-step process that includes the oligomerization of ethylene followed by oxidation. The result are linear primary alcohols with an even number of carbon atoms. This process is captured in Reaction Scheme 3. The (c) trialkyl aluminum of Formula (II) in which R2, R3and R4can be independently selected from a C4 to C20 alkyl is an intermediate in the synthesis of the alpha-olefins. These can be utilized as reagents and reacted with the alpha-olefins to form branched alcohols upon oxidation. Reaction Scheme 3 illustrates the reaction of 1-butene with (c) trialkyl aluminum of Formula (II) in which R2, R3and R4can be independently selected from a C4 to C20 alkyl to produce a composition of 2-ethyl branched alcohols upon oxidation and hydrolysis, as provided herein. In principle, any C3 (propylene) and greater alpha-olefin can be used and would generate 2-branches of varying lengths. For example, the use of 1-hexene could generate a composition of alcohols with 2-butyl branches, while 1- propylene would generate methyl branches. Other examples are possible. Reaction Scheme 3 Examples Materials 1-Dodecene: 95%; 1-Hexene: 97%; 1-Octene: 98%; and 1-Decene: 94% each acquired from Sigma-Aldrich and purged with nitrogen and dried over activated alumina before use. Triethylaluminum: 25 wt.% in toluene (Sigma-Aldrich). Toluene: Anhydrous, 99.8% (Sigma-Aldrich), dried over activated alumina before use. Catalyst: (E)-((2,6-diisopropylphenyl)(2-methyl-3-(octylimino)butan-2- yl)amino)trimethyl hafnium (Boulder Scientific Co.). Activating cocatalyst: [(C16-18H33-37)2CH3NH] tetrakis(pentafluorophenyl)borate salt (Boulder Scientific Co.). Methanol ACS grade (Sigma-Aldrich). HCl 12M (Sigma-Aldrich), diluted to 3M with water Dry Air was obtained by taking lab air and drying it through a column of Drierite. 1H-NMR spectroscopy (NMR Analysis) – 1H NMR spectra were recorded on a Bruker AV-400 spectrometer operating at room temperature. As used herein, room temperature is 23oC. GC / MS Analysis The oxidation products of the branched aluminum alkyl were analyzed by GC / MS. Instrument and settings details are shown below in Table 1. Table 1. GC-MS instrument and method details for analysis of oxidized aluminum alkyls Instrument: Agilent 6890N GC system with Agilent 5973 MSD with EI Source Agilent 7683 injector with 7683 Automatic Liquid Sampler Examples 1-9 The following Examples (EX) 1-9 provide a series of reactions that demonstrate the breadth of 1-alkenes that can undergo carboalumination of the present disclosure, along with determination of the conditions. The following 1-alkenes were used: 1-hexene (C6), 1-octene (C8), 1-decene (C10), 1-dodecene (C12), and 1-tetradecene (C14). The trialkyl aluminum used was triethyl aluminum, which was kept at a constant molar equivalent of 0.4, relative to the 1- alkene, except for EX 6, where it was lowered to 0.35. The catalyst and activating cocatalyst loading for EX 1-4 was kept at 0.00024 and 0.0002 equivalents, respectively. EX 5 used a catalyst and activating cocatalyst loading that was 50% of EX 1-4. EX 1 to 5 were smaller scale reactions and the experimental is described below. EX 6 was a large-scale reaction with oxidation of the trialkyl aluminum and isolation of 2-ethyl-dodecanol. Table 2. EX 1-10 Overview EX 1-Alkene AlR3 Activating Catalyst 1 molar aluminum cocatalyst (molar i l t l l i l t - demons raed a e -a enes s ar ng rom C6 ( - exene) o C ( -dodecene) undergo carboalumination with low catalyst and activating cocatalyst loading. Each reaction was analyzed by1H-NMR spectroscopy before and after the addition of the activating cocatalyst and catalyst. After the addition of the catalyst and activating cocatalyst, and upon stirring for 16 hours, the resonances assignable to double bond (6-5 ppm) disappeared. This is consistent with consumption of the 1-alkene and carboalumination. EX 5 demonstrated that the catalyst and activating cocatalyst loading can be reduced to 50% and still maintain complete consumption of 1-dodecene. EX 6-9 were the synthesis and isolation of 2-ethyl-decanol, 2-ethyl-dodecanol, and 2-ethyl-tetradecanol. EX 10 demonstrated that trioctyl aluminum can be used as the aluminum reagent. EX 1: Synthesis of tris(2-ethylhexanyl)aluminum In a nitrogen filled glovebox, a 40 mL glass vial was charged with 1-hexene (1.18 ml, 9.5 mmol), triethyl aluminum (2 ml of 25 wt.% solution in toluene, 3.8 mmol) and activating cocatalyst (2.3 µmol). The catalyst (1.9 µmol) was added to the vial to initiate the reaction at room temperature. After stirring overnight (16 hrs), a sample was taken for NMR analysis (FIG. 1), confirming that the reaction was complete. EX 2: Synthesis of tris(2-ethyloctanyl)aluminum In a nitrogen filled glovebox, a 40 mL glass vial was charged with 1-octene (1.49 ml, 9.5 mmol), triethyl aluminum (2 ml of 25 wt.% solution in toluene, 3.8 mmol) and activating cocatalyst (2.3 µmol). The catalyst (1.9 µmol) was added to the vial to initiate the reaction at room temperature. After stirring overnight (16 hrs), a sample was taken for NMR analysis (FIG. 2), confirming that the reaction was complete. EX 3: Synthesis of tris(2-ethyldecyl)aluminum In a nitrogen filled glovebox, a 40 mL glass vial was charged with 1-decene (1.8 ml, 9.5 mmol), triethyl aluminum (2 ml of 25 wt.% solution in toluene, 3.8 mmol) and borate activating cocatalyst (2.3 µmol). The catalyst (1.9 µmol) was added to the vial to initiate the reaction at room temperature. After stirring overnight (16 hrs), a sample was taken for NMR analysis (FIG. 3), confirming that the reaction was complete. EX 4: Synthesis of tris(2-ethyldodecyl)aluminum In a nitrogen filled glovebox, a 40 mL glass vial was charged with 1-dodecene (2.1 ml, 9.5 mmol), triethyl aluminum (2 ml of 25 wt.% solution in toluene, 3.8 mmol) and activating cocatalyst (2.3 µmol). The catalyst (1.9 µmol) was added to the vial to initiate the reaction at room temperature. After stirring overnight (16 hrs), a sample was taken for NMR analysis (FIG. 4), confirming that the reaction was complete. EX 5: Synthesis of tris(2-ethyldodecyl)aluminum with low catalyst dosage In a nitrogen filled glovebox, a 40 mL glass vial was charged with 1-dodecene (2.1 ml, 9.5 mmol), triethyl aluminum (2 ml of 25 wt.% solution in toluene, 3.8 mmol) and activating cocatalyst (1.15 µmol). The catalyst (0.95 µmol) was added to the vial to initiate the reaction at room temperature. After stirring overnight (16 hrs), a sample was taken for NMR analysis (FIG. 5), confirming that the reaction was complete. EX 6: Synthesis and isolation of 2-ethyl-dodecanol In a nitrogen filled glovebox, a 400 mL glass vessel was charged with 1-dodecene (154 ml, 0.692 mol), triethyl aluminum (130 ml of 25 wt.% solution in toluene, 0.247 mol) and activating cocatalyst (0.148 mmol). The catalyst (73 mg, 0.123 mmol) was dissolved in toluene (5 mL) and added to the vessel to initiate the reaction at room temperature. After stirring overnight (16 hrs), a sample (0.5 mL) was taken for NMR analysis, and another aliquot (0.5 mL) was hydrolyzed by methanol / HCl for subsequent GC / MS analysis (FIG.6). The1H-NMR spectrum, FIG.6, showed that 1-dodecene vinyl group was completely consumed, showing effective carboalumination. The GC / MS showed that the starting 1- dodecene (MW 168) mostly disappeared after reaction, and the new main peak (MW 198) is consistent with the expected hydrolyzed product 2-ethyl dodecane. The remaining sample was diluted with toluene (100 mL) and dry air was slowly bubbled into the solution with stirring. The air rate was modulated to ensure that the reaction temperature did not exceed 50 °C. The air addition was carried out overnight (16 h) while the circulation was turned off on the glovebox and it was slowly purged with N2. The following day, the solution was removed from the nitrogen filled glovebox and, in a fume hood, the contents were transferred to a 1 L flask. A solution of hydrochloric acid (3M, 300 mL) was added slowly, and the reaction mixture was allowed to stir for 30 minutes. The contents were transferred to a separatory funnel and the organic layer was isolated, dried with anhydrous MgSO4(10 grams), and filtered. The organics were placed on a rotary evaporator at 25 mm Hg and a water bath temperature of 45 °C. This afforded 128 grams of material. The above carboalumination, oxidation, and hydrolysis reaction was undertaken a total of 3 times to afford a total mass of 385 grams. Analysis by GC / MS showed the composition below in Table 3. Table 3. Composition of carboalumination process Mass of Solvent (g) Saturated Olefinic 2-Et- Balance The mixture was purified by distillation using a spinning band column. The 385.4 g mixture was first loaded into the 1-L pot. Once the mixture was loaded, the pot was connected to the bottom of the spinning band column and placed into the heating mantle. A magnetic stir bar was used to achieve good mixing and even boiling. The separation process was operated under two different pressures. The solvent and some light components were removed first at 100 mmHg. A reflux to distillate ratio of 8:1 was used. The lights removal ended after the overhead vapor temperature dropped as shown in FIG.7, which shows temperature histories for the overhead vapor, liquid in the pot and the heating mantle surface during the distillation process. This temperature drop indicates all the light solvent had been removed from the liquid mixture. The overhead vapor temperature during the solvent removal stage remained at about 48oC. A total of 35.9 grams of overhead distillate was collected with the first cut (Cut #1) as shown in Table 4 that gives the composition and weights of all cuts and the bottom residuals collected. As seen in Table 4, Cut #1 contained 98.86% solvent (Toluene) with the balance of other unknown lights. Table 4. Compositions and % mass of all distillate cuts and bottom residuals Sample Solvent Saturate Olefinic Product Balance Mass (g).4.9.4.4.5.7.2 avoid overly high liquid temperature due to the high boiling points of the remaining components. Cuts # 2 and #3 were to remove the saturates and olefins, which are estimated to have essentially the same normal boiling point at about 249oC. Cut #2 contained 76.6% saturates, 4.52% olefins, and 17.67% unidentified others which were lighter than the product. The overhead vapor temperature ranged from 56 to 92oC during Cut #2 collection. Cut #3 contained 41.57% saturates, 2.71% olefins, and 10.92% unidentified others which were lighter than the product. The overhead vapor temperature ranged from 90 to 112oC during Cut #3 collection. There was 44.8% of product in Cut #3 as its normal boiling point is only about 25oC higher than the saturates and olefins. To ensure high purity product was obtained, a small transient cut (Cut #4 – 32.5 grams) was taken to remove any remaining saturates and olefins and similar components before collecting the alcohol product as overhead distillate. The overhead vapor temperature ranged from 112 to 123oC during Cut #4 collection. Cut #4 contained 91.43% product with the balance of mostly unidentified components. The alcohol product was collected in Cut #5. A total of 80.7 grams was collected and the product concentration was 96.37%, with the balance being mostly the unidentified heavies. The overhead vapor temperature ranged from 121 to 124.5oC during Cut #5 collection. The distillation was shut down when the overhead vapor temperature started to drop and the distillate flow rate decreased significantly.111.2 grams of bottom residuals were collected in the pot, which contains 97.37% of the unidentified heavies. Another distillation was undertaken, where Cuts #2, #3, and #4 from Table 4 were combined to give a mass of 144.5 grams. This was distilled in a similar fashion to afford 4 cuts and a bottom fraction. The fourth cut was over 95% 2-ethyl-dodecanol with a mass of 40.1 grams. Total mass of 2-ethyl-dodecanol from both distillations was 120.1 grams. This corresponds to an isolated yield of 28.4% from 1-dodecene. EX 7: Synthesis and isolation of 2-ethyl-decanol In a nitrogen filled glovebox, a 1L glass vessel was charged with 1-decene (113.8 ml, 601.3 mol), triethyl aluminum (130 ml of 25 wt.% solution in toluene, 0.240 mol) and activating cocatalyst (0.072 mmol). The catalyst (36 mg, 0.06 mmol) was dissolved in toluene (5 mL) and added to the vessel to initiate the reaction at room temperature. The sample was stirred overnight, and an aliquot was removed and analyzed by NMR spectroscopy, which showed complete conversion of 1-decene. The sample was diluted with toluene (400 mL) and dry air was slowly bubbled in the solution with stirring The air rate was modulated to ensure that the reaction temperature did not exceed 60 °C. The air addition was carried out overnight (16 h) while the glovebox was purged with N2. The following day, the solution was removed from the glovebox. A solution of hydrochloric acid (3M, 300 mL) was added slowly, and the reaction mixture was allowed to stir for 30 minutes. The contents were transferred to a separatory funnel and the organic layer was isolated. The organic layer was again washed with hydrochloric acid (3 M, 300 mL) for 30 mins. The organic layer was isolated, dried with anhydrous MgSO4 (10 grams), and filtered. The organics were placed on a rotary evaporator at 10 mm Hg and a water bath temperature of 80 °C. The above procedure was repeated 2 more times to afford 322 grams of combined crude 2-ethyl-decanol. The material was distilled using the spinning band column described in EX 6. The product distilled at a pressure of 2 mm Hg with a vapor temperature range of 80-85 °C. The isolated yield of 2-ethyl-decanol was 60.4 grams (18.2 % yield) EX 8: Synthesis and isolation of 2-ethyl-tetradecanol In a nitrogen filled glovebox, a 1L glass vessel was charged with 1-tetradecene (138.2 ml, 0.5454 mol), triethyl aluminum (117.9 ml of 25 wt.% solution in toluene, 0.2182 mol) and activating cocatalyst (0.055 mmol). The catalyst (38 mg, 0.065 mmol) was dissolved in toluene (5 mL) and added to the vessel to initiate the reaction at room temperature. The sample was stirred overnight, and an aliquot was removed and analyzed by NMR spectroscopy, which showed complete conversion of 1-tetradecene. The sample was diluted with toluene (400 mL) and dry air was slowly bubbled in the solution with stirring. The air rate was modulated to ensure that the reaction temperature did not exceed 60 °C. The air addition was carried out overnight (16 h) while the glovebox was slowly purged with N2. The following day, the solution was removed from the glovebox. A solution of hydrochloric acid (3M, 300 mL) was added slowly, and the reaction mixture was allowed to stir for 30 minutes. The contents were transferred to a separatory funnel and the organic layer was isolated. The organic layer was again washed with hydrochloric acid (3 M, 300 mL) for 30 mins. The organic layer was isolated, dried with anhydrous MgSO4(10 grams), and filtered. The organics were placed on a rotary evaporator at 10 mm Hg and a water bath temperature of 80 °C. The above procedure was repeated 2 more times to afford 60 grams of combined crude 2-ethyl-tetradecanol. The material was distilled using spinning band column described in EX 6. The cut at 100 °C at a pressure of 2 mm Hg contained 2-ethyl-tetradecanol. The yield of 2-ethyl-tetradecanol was 60 grams. The distillation was stopped for safety reasons because the liquid temperature reached 400 °C. GC analysis of the bottoms showed it to be 60% 2-ethyl-tetradecanol (84 grams) The combined yield is 144 g; 36.4 % EX 9: Synthesis and isolation of 2-ethyl-dodecanol (1-dodecanol:AlEt3;0.6:1) In a nitrogen filled glovebox, a 1L glass vessel was charged with 1-dododecene (24.6 ml, 0.111 mol), triethyl aluminum (100 ml of 25 wt.% solution in toluene, 0.185 mol) and activating cocatalyst (0.022 mmol). The catalyst (0.0185 mmol) was dissolved in toluene (5 mL) and added to the vessel to initiate the reaction at room temperature. The sample was stirred overnight, and an aliquot was removed and analyzed by NMR spectroscopy, which showed complete conversion of 1-dodecene. The sample was diluted with toluene (200 mL) and dry air was slowly bubbled in the solution with stirring. The air rate was modulated to ensure that the reaction temperature did not exceed 60 °C. The air addition was carried out over (6 h) while the glovebox was purged with N2. The following day, the solution was removed from the glovebox. A solution of sulfuric acid (20%, 300 mL) was added slowly, and the reaction mixture was allowed to stir for 30 minutes. The contents were transferred to a separatory funnel and the organic layer was isolated. The organic layer was again washed with sulfuric acid (20% 300 mL) for 30 mins. The organic layer was isolated, dried with anhydrous MgSO4(10 grams), and filtered. The organics were placed on a rotary evaporator at 5 mm Hg and a water bath temperature of 95 °C. The isolated mass was 20 grams, and it was analyzed by GC / MS and shown to be 53% 2-ethyl-dodecanol, 19% 3-methyl- tridecane (the product of incomplete Al-R oxidation) and the rest being a mixture of other compounds. The mixture was not purified to isolated 2-ethyl-dodecanol but the procedure in EX 6 would be suitable. EX 10: Synthesis of tris(2-butyloctanyl)aluminum In a nitrogen filled glovebox, a 40 mL glass vial was charged with 1-hexene (1.38 ml, 11.42 mmol), trioctyl aluminum (10 ml of 25 wt.% solution in hexane, 4.57 mmol) and activating cocatalyst (1.4 µmol). The catalyst (1.2 µmol) was added to the vial to initiate the reaction at room temperature. After stirring overnight (16 hrs), a sample was taken for NMR analysis, confirming that the reaction was complete. The reaction was removed from the glovebox and hydrolyzed with 10% HCl (20 mL). The organic layer was isolated an analyzed by GC / MS, which showed 5-methyl-tridecane as the main product (62%). Following the above EX 6-9, if the reaction was quenched with air instead of acid it would have afforded 2-butyl-decanol.

Claims

What is Claimed is:

1. A method of producing a branched trialkyl aluminum, comprising: providing a reaction mixture of (a), (b) and (c), wherein: (a) is an alpha-olefin of Formula (I): wherein R1is a C2 to C18 alkyl;(b) is a trialkyl aluminum of Formula : wherein each of R2, R3and R4isC1 to C24 alkyl; and (c) is a catalyst system comprising a procatalyst of Formula (III): where for X1eachto C4 alkyl; R5-R13are independently in each occurrence hydrogen, halogen, substituted or unsubstituted substituted or unsubstituted C1 to C20 alkyl, or C6 to C20 aryl, or two or more adjacent R groups are joined together thereby forming a saturated, unsaturated, or aromatic ring; and an activating cocatalyst; and reacting (a) and (b) in the presence of (c) to produce the branched trialkyl aluminum of Formula (IV):V).

2. The method of claim 1, wherein each of R2, R3and R4is independently selected from a C3 to C24 linear alkyl.

3. The method of any one of claims 1-2, wherein R1is a C2 to C14 alkyl; or a C4 to C10 alkyl.

4. The method of any one of claims 1-3, wherein R1has an even number of carbons.

5. The method of any one of claims 1-4, wherein two or more of (a) the alpha-olefin of Formula (I) in the reaction mixture has a different R1moiety.

6. The method of any one of claims 1-5, wherein each of R2, R3and R4is independently selected from a C2 to C10 alkyl or a C2 to C6 alkyl.

7. The method of any one of claims 1-5, wherein each of the alkyl of R2, R3and R4has an even number of carbons.

8. The method of any one of claims 1-7, wherein for Formula (II) two or more of R2, R3and R4have the same size alkyl moiety.

9. The method of any one of claims 1-7, wherein the trialkyl aluminum of Formula (II) is heteroleptic.

10. The method of claim 1, wherein R1is a C10 alkyl and each of R2, R3and R4is a C2 alkyl.

11. The method of any one of claims 1-10, comprising:oxidizing the branched trialkyl aluminum of Formula (IV) to produce an aluminum alkoxide; and hydrolyzing the aluminum alkoxide to produce a branched alcohol.

12. The method of claim 11, wherein the branched alcohol is a 2-ethyl branched alcohol having C6 to C20 total carbons.

13. The method of any one of claims 1-12, wherein the procatalyst of Formula (III) is present in the reaction mixture at a molar equivalent of 0.01 to 0.0001 relative to (a) the alpha-olefin of Formula (I).

14. The method of any one of claims 1-13, wherein the activating cocatalyst is selected from the group consisting of [(C16-18H33-37)2CH3NH] tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, or ferrocenium tetrakis(pentafluorophenyl)borate.

15. The method of any one of claims 1-14, wherein the procatalyst of Formula (III) is: .

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